Pirelli’s motorsport director Paul Hembery has rejected the idea that the changes made by the Italian tire manufacturer during the season changed the direction of the 2013 Formula One world championship.

Following a series of issues with the initial design of tire, Pirelli were forced into making changes that came into effect at the German Grand Prix after a safety concern arose at Silverstone. Since then, Sebastian Vettel has won eight of the last nine races, leading many to suggest that Red Bull’s competitive advantage grew thanks to the alterations. However, Hembery explained to the official Formula One website that he does not believe that the team’s achievements should be understated.

“Nobody knows the real answer,” he said. “Yes, Red Bull was leading before we made the change – they’ve always been quick in qualifying but suffered in the race. Mercedes were always quick in qualifying and suffered in the race and Lotus were always very competitive in the race, so there are a lot of factors that haven’t changed at all, and that’s all we can say.

“You could pretty much guarantee that Red Bull Racing would have won after all the changes they’ve made after the summer break and the way the tires have been used by them. They’ve done a very good engineering job in the second part of the season, as they always do. The way they work and develop right to the end, they need to get some credit sometimes for the fantastic job the team has done around Sebastian.”

Many teams have cited the tire changes as being decisive in their season, with Force India particularly appearing to struggle whilst Sauber have made great strides forward. An investigation by MotorSportsTalk writer Keith Collantine suggests that the case for Red Bull benefitting from the tire changes is certainly well-reasoned, but it is also worth noting that Vettel’s fine run of form actually started before the alterations. He finished in second place at the Monaco Grand Prix before winning in Canada, and he would have won the British Grand Prix had it not been for a gearbox failure.